This invention relates to thermal blankets used in a medical setting to deliver a bath of a thermally-controlled medium to a patient.
The thermal blanket prior art is best expressed in our prior U.S. Pat. No. 4,572,188 entitled xe2x80x9cAIRFLOW COVER FOR CONTROLLING BODY TEMPERATURE.xe2x80x9d In our patent, a self-erecting, inflatable airflow cover is inflated by the introduction into the cover of a thermally-controlled inflating medium, such as warmed air. When inflated, the cover self-erects about a patient, thereby creating an ambient environment about the patient, the thermal characteristics of which are determined by the temperature of the inflating medium. Holes on the underside of our prior art airflow cover exhaust the thermally-controlled, inflating medium from inside the cover to the interior of the erected structure. Our airflow cover is intended for the treatment of hypothermia, as might occur postoperatively.
Evaluation of our airflow cover by skilled practitioners has resulted in general approbation: the opinion is that the airflow cover efficiently and effectively accomplishes its purpose of giving a thermally-controlled bath. We have realized, however, that, while our prior art airflow cover achieves its objective, certain improvements to it are necessary in order to realize additional clinical objectives and to enjoy further advantages in its use.
We have improved the clinical usefulness of our self-erecting airflow cover by observing that controlling the contour of its inflatable portion at its head end to define a generally concave non-inflatable portion will permit a care giver to more easily observe a patent""s head, face, neck and chest. Finally, we have observed that limited venting of the thermally controlled inflating medium from the edges of the cover results in more efficient, more uniform heating within the cover. We have also observed that it is good clinical practice to keep the area of the care site in the vicinity of the patient""s head and face as clean as possible. Still further, we have observed that modification of the foot end of the self-erecting airflow cover to define a non-inflatable but erectable drape section retains heat from the inflating medium to warm the patient""s feet and insulate the bare skin of the feet from excessive heat from the inlet hose. Finally, we have observed that our self-erecting airflow cover may be advantageously adapted to thermally control specific partial portions of the patient such as the legs and lower body or the arms and upper body, leaving other areas of the patient available for care and treatment. Moreover, an end portion of the cover may be adhesively attached to the patient to prevent the migration of air toward a care area. Finally, a protective sleeve may be slideably mounted on a connected heater tube adjacent the patient to prevent the heater tube from contacting the patient.
These observations have resulted in an improved thermal blanket and method therefor in which a self-erecting inflatable covering has a head end, a foot end, two edges, and an undersurface. An inflating inlet adjacent the foot (or head) end admits a thermally-controlled inflating medium into the covering. An aperture array on the undersurface of the covering exhausts the thermally controlled inflating medium from the covering into the structure created when the covering self-erects upon inflation. The improvements to this basic structural complement include an uninflatable section at the head (or foot) end of the covering, exhaust port openings at the edges of the cover, an absorbent bib or adhesive strip attached to the covering at the head (or foot) end adjacent the uninflatable section, in uninflatable erectable drape section at the foot end of the covering, a heater tube protective cover and structural features that make the covering simple and economical to produce. In the case of an upper body covering, the positions of the inflating inlet and the uninflatable section are reversed from that of other coverings. In the case of an upper body covering, the inflating inlet is positioned at the head end of the covering while the uninflatable section is arranged at the foot end of the covering.
With these improvements, the thermal blankets, when inflated and erected over a patient, delivers the thermally-controlled inflating medium into the interior of the structure covering the patient, thereby thermally bathing the patient. The first improvement permits full viewing of the head and face of the patient from almost any aspect around the thermal blanket. The exhaust port openings increase the rate of circulation of the inflating medium within the blanket, thereby increasing the temperature within the structure and making the temperature distribution more uniform. The absorbent bib soaks up and retains liquid which might otherwise spread over the care site in the area of the patient""s head or other body area. Such liquids can include the patient""own perspiration, blood, vomit, saliva, or liquids which are administered to the patient. The adhesive strip acts to seal the head (or foot) end of the inflated structure. The non-inflatable erectable drape section at the foot end of a covering encompassing the lower extremities retains heat around the patient""s feet and insulates the bare skin of the legs and/or feet. The protective cover for the heater tube prevents an attached heater tube from contacting the patient.
From another aspect, the invention is a thermal blanket for covering and bathing a person in a thermally-controlled medium. The thermal blanket includes a flexible base sheet having a head end, a foot end, two edges, and a plurality of apertures opening between the first and second surface of the base sheet. An overlying material sheet is attached to the first surface of the base sheet by a plurality of discontinuous seams which form the material sheet into a plurality of substantially parallel, inflatable chambers. A continuous seam is provided between the material sheet and the base sheet at the head (or foot) end to form a non-inflatable viewing recess at the head (or foot) end. Exhaust port openings are provided through the material sheet to vent the medium from the chambers away from the base sheet. An absorbent bib is attached to the head (or foot) end in the vicinity of the viewing recess. In coverings encompassing the lower extremities, a continuous seam is provided between the material sheet and the base sheet at the foot end to form a non-inflatable, erectable drape section to cover the patient""s legs and/or feet.
Therefore the invention accomplishes the important objective of providing a self-erecting, inflatable thermal blanket that permits a relatively unobstructed view of a care site when in use.
Another object is the efficient and uniform heating of the interior of the structure created when the blanket is inflated with a heat inflating medium.
A further objective is providing a covering for a patient""s legs and/or feet that helps retain the heat inflating medium around the patient.
A still further objective is the provision of such a blanket with a means for maintaining the cleanliness of the care site.
A still further objective is to provide the ability to select coverings adapted for specific partial areas of the patient leaving other areas exposed for care and treatment.
The advantageous simplified structure of the thermal blanket make its production straight forward and economical.
These and other important objectives and advantages will become evident when the detailed description of the invention is read with reference to the below-summarized drawings, in which:
FIG. 1 is a side elevation view of a thermal blanket constructed in accordance with a first aspect of the invention, with the blanket in use, with associated thermal apparatus indicated schematically;
FIG. 2 is an enlarged top plan view of the thermal blanket opened flat;
FIG. 3 is an enlarged sectional view taken along 3xe2x80x943 of FIG. 2;
FIG. 4 is a further enlarged sectional view taken along line 4xe2x80x944 of FIG. 3;
FIG. 5 is a partial underside view of the thermal blanket;
FIG. 6 is a partial diagrammatic top plan view of a thermal blanket constructed in accordance with a second aspect of the invention, with a partially constructed foot drape;
FIG. 7 is a partial projected view of a fully constructed thermal blanket of FIG. 6 in use, with the patient""s feet illustrated by hidden lines underlying the foot drape.
FIG. 8 is a top plan view of a partially constructed thermal blanket in accordance with a third aspect of the invention, for thermally covering the pelvic area and lower extremities of a patient;
FIG. 9 is a partial projected view of a fully constructed thermal blanket of FIG. 8 in use;
FIG. 10 is a top plan view of a thermal blanket constructed in accordance with a fourth aspect of the present invention, for thermally covering the chest and upper extremities of a patient; and
FIG. 11 is a partial projected view of a fully constructed thermal blanket of FIG. 10 in use.